1. Field of the Invention
The present invention relates to a noise control apparatus for a vacuum cleaner, and more particularly to a noise control apparatus for a vacuum cleaner capable of positively controlling noise generated from a dust-sucking motor and an impeller.
2. Description of the Prior Art
Generally, noise generated in vacuum cleaners may be present in a wide frequency band. For removing such noise, various proposals has been made. For example, there have been proposed an installation of a sound-absorbing member surrounding both an impeller and a motor disposed in a vacuum cleaner, as disclosed in Japanese Patent Laid-open Publication No. Sho 62-32903, as well as a provision for an elongated fluid passage (air passage) in a vacuum cleaner.
Although these noise control methods exhibit superior effects for removing noise having a frequency band of 500 Hz or above, they encounter problems in removing noise of a lower frequency band. For removing such lower frequency noise, a sound-absorbing member having an increased thickness should be used. Due to such an increase in thickness, however installation of the sound-absorbing member in the interior of vacuum cleaner may be difficult.